Summary
International Symposium on Antennas and Propagation
2009
Session Number:2A1
Session:
Number:2A1-4
A Coplanar Capacitively Coupled Probe Fed Microstrip Antenna for Wireless Applications
Veeresh G. Kasabegoudar, K. J. Vinoy,
pp.297-300
Publication Date:2009/10/21
Online ISSN:2188-5079
Summary:
Microstrip antennas are versatile candidates for the modern broadband wireless applications because of their numerous advantages [1]. Yet most conventional geometries typically have narrow bandwidth, which limits their use in several applications. However it has been shown by several researchers that the bandwidth of microstrip antenna can be significantly improved by altering its basic configuration. These alterations include, increasing the height (or thickness) of the substrate, cutting slots in the basic shapes, changing the shape of the geometry, or using multi-layer techniques [2]. Bandwidth enhancement can also be achieved by modifying the feed networks (elements) such as meandered probe or changing the probe to L-shape or by reactive loading [3]. Many of these have relatively complex assembly, which in some cases is contrary to the fundamental attraction of microstrip antennas. This group has reported a simple modification to the feed arrangement by which the impedance bandwidth of the antenna (S11<-10dB) could be enhanced to 50% [4]. It is well known that the bandwidth enhancement can be achieved by increasing the overall height of the dielectric medium. However this introduces the large probe inductance, which could be cancelled out by the capacitive feed strip placed parallel to one of the radiating edges of the patch. Although suspended configurations are simple to implement and offer numerous advantages, the use of air gap increases the height/volume of the antenna which is undesired in several (compact) applications. In this work we propose a design that uses small air gap for the similar antenna designs reported earlier. The antenna developed here is suitable for various wireless applications like ISM (2.4-2.5 GHz), PCS cellular spectrum widely licensed across the US at 1.9 GHz, broadband wireless commercial service delivery in US (2.3GHz) etc. The basic design of the antenna is presented in the next section. Its design starts with the selection of center frequency as the design approach can be easily scaled to any frequency of interest [4]. Simulation studies to determine the dimensions of the key design parameters and the slot are presented in Section 3. Experimental validations are presented in the later part of Section 3. Conclusions of this study are given in Section 4.